1. Field of the Invention
The present invention relates to a recorder, and more particularly to an apparatus for recording moving image data along with thumbnail images.
2. Related Background Art
As an apparatus for recording and reproducing moving images, a video tape recorder (VTR) is known which records analog image signals on a magnetic tape. In addition to such an apparatus for recording and reproducing analog image signals, a digital VTR and a digital recorder have been proposed recently. The digital VTR converts analog image signals into digital image signals and records the digital image signals on a magnetic tape. The digital recorder records digital image signals on a disc type recording medium such as a solid state disk and a magneto-optical disc or a solid state memory such as a flash memory and an SRAM.
These apparatuses reduce an information amount by compressing digital image signals so that a large amount of moving or still image information can be stored in a small storage capacity. Moving image recording systems of various kinds have been proposed which compress moving image signals by utilizing a combination of various compression techniques to reduce the data amount and store the compressed data in a solid state memory, a magneto-optical disc or the like.
A moving image compressing and recording method is mainly divided into two methods depending upon a recording medium for storing moving image data.
One method sequentially records moving image data on a magnetic tape or the like. This method is, however, associated with the difficulty of searching a desired scene or changing the order of scenes.
The other method records each moving image scene on a medium capable of random access such as a solid state memory and a magneto-optical disc. With this method, since the medium is capable of random access, scene read/write can be performed starting at any address. It is therefore easy to directly search and reproduce a desired moving image scene or change the order of scenes.
In order to directly search a desired scene, as shown in FIG. 6A a digital still camera or the like for recording still image signals generally produces beforehand still image thumbnail images (representative images) by reducing the size of main images and displays a list of thumbnail images on the screen. Since the main image of the digital still camera is a still image, the characteristics of a main image can be seen from one reduced thumbnail image.
In contrast, since the main image of a video camera dealing with moving images is a moving image, the first frame of each scene is extracted from main images of moving images to produce thumbnail still images as shown in FIG. 6B. An approach has been proposed which forms thumbnail images functioning as search indices, as moving images as shown in FIG. 6C.
If moving images which is main images are subjected to effect processes (particularly fade-in effect, wipe-in effect, cross fading effect and the like), a thumbnail image produced from the start frame, which is subjected to the effect process, does not show well the characteristics of the main moving image.
If moving image data containing a large amount of data subjected to the effect process is used for creating a moving image thumbnail image, this thumbnail image does not show well the characteristics of the main moving image.